Apparatus and method for impressing patterns in a slip-formed concrete wall

ABSTRACT

An apparatus and a method for impressing three-dimensional patterns in a slip-formed concrete wall. At least one impression roller is provided at the discharge end of a slip form. The impression roller includes an outer periphery, provided with a layer or coating of resilient material. The layer is pre-formed or pre-cast to include an aesthetically pleasing, three-dimensional pattern. The axis of the roller is maintained in parallel relation to the plane of the exposed surface of the wall, with the outer periphery of the roller slightly depressed into the wall surface. As the uncured concrete wall emerges from the slip form, the impression roller places a pattern into the wall surface which corresponds to the pattern on the roller. Movement of the roller along the wall causes the impression roller to rotate, impressing successively formed portions of the wall with the pattern. Additional rollers may be used to impress patterns on the opposing wall surface, as well as the top wall surface. After the concrete wall has fully cured, stain, paint, or other decorative features may be applied to the pattern, adding further visual interest and variety.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of copending application Ser. No.09/918,617, filed on Jul. 30, 2001, now U.S. Pat. No. ______,incorporated herein by reference in its entirety.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not Applicable

INCORPORATION-BY-REFERENCE OF MATERIAL SUBMITTED ON A COMPACT DISC

Not Applicable

NOTICE OF MATERIAL SUBJECT TO COPYRIGHT PROTECTION

A portion of the material in this patent document is subject tocopyright protection under the copyright laws of the United States andof other countries. The owner of the copyright rights has no objectionto the facsimile reproduction by anyone of the patent document or thepatent disclosure, as it appears in the United States Patent andTrademark Office publicly available file or records, but otherwisereserves all copyright rights whatsoever. The copyright owner does nothereby waive any of its rights to have this patent document maintainedin secrecy, including without limitation its rights pursuant to 37C.F.R. § 1.14.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates generally to devices for slip-forming concretestructures, such as divider walls, retaining walls, and other verticallyextending barriers. More specifically, the invention pertains to anapparatus including one or more impression rollers, strategicallypositioned at the discharge end of a slip-form, to impress aestheticpatterns on the sidewalls and on the top wall of the slip-formedstructure, just after the structure has been formed and before theconcrete has cured.

2. Description of the Prior Art

Concrete walls have long been employed in freeway construction, both asdivider walls between opposing directions of traffic, and as retainerwalls extending along the sides of the outermost freeway lanes. Concretewalls are also used as barrier walls along property lines, and asaesthetic features in industrial or commercial landscaping. The need forconcrete walls also arises to prevent erosion along the periphery ofman-made lakes, and along river banks and coast lines.

Historically, concrete forms have been constructed from plywood andrestraining posts assembled on the wall site, to shape, size, and directthe wall. After the concrete has been poured into the form and has curedsufficiently, the form is disassembled and another form is constructedfor the adjacent wall section. This process is both labor intensive, andslow, owing to the amount of construction and disassembly of forms whichit necessitates.

A relatively recent development in the concrete wall constructionindustry is the application of a technique known as slip-forming.Instead of constructing a form on site, a mobile slip form is used. Themobile slip form is mounted to the frame of a motorized vehicle. A guideline is laid out defining one edge of the wall to be formed. The frameof the vehicle includes fore and aft alignment rods, maintained incontingent relation with the guide line by the operator.

As the motorized vehicle progresses forwardly down the guide line, freshconcrete is continuously poured into the slip form. The slump andconstituent materials of the concrete mix are such that multiplevibrators, immersed within the slip form, are necessary to ensurethorough consolidation of the mix. When the formed concrete emerges fromthe output, or trailing edge of the form, it has smooth sidewalls and asmooth top wall.

If the slip-formed wall is relatively short, on the order of three tofour feet, the entire wall including a spread footer, can be formedwithout structural reinforcement, in a single pass of the slip-formmachine. If the wall is higher, a reinforcement bar cage is typicallyused in combination with a larger and formed, footer. Although thereinforcement cage must be constructed beforehand, the slip-formconcrete pour technique has still been accomplished in a single pass ofthe slip-form machine, even for a tall wall up to eight feet, or so.

There are a number of commercially available slip-form machines. Onesuch machine is the Commander III, manufactured by the GOMACOCorporation, of Ida Grove, Iowa. This machine has been used successfullyto slip-form vertical walls up to 8′8″ high, and to slip-form roadways.At least one paving operation at a dairy farm is known, using theCommander III, in which a free-floating steel roller was used to imprinta cobblestone pattern on the flat surface of the just-formed concreteroadway. The roller included rigid, rib-like protrusions on its outerperiphery, corresponding to the cobblestone pattern. The pattern wasimpressed in the roadway to provide traction for the cattle, to keeptheir feet from slipping.

However, when slip-forming walls using known prior art machines, thesidewalls and the top wall emerge from the form uniformly smooth, andcure having the same smooth appearance. These walls have been recognizedas visually unappealing for certain applications, so surface amendmentshave been added to the smooth surface. Walls have been colored withstain or paint, or decorative plates have been applied to the smoothwalls after the concrete has set. These surface amendments consumeadditional time and materials, and increase the overall cost of the wallconstruction.

Therefore, the need exists for an apparatus which slip-forms a wall andconcurrently creates a visually appealing pattern or impression in thesurface of at least one sidewall of the wall.

The need exists for an apparatus which can be used in conjunction withexisting slip-form machines, to impress a visually appealing pattern inthe exposed surface of a slip-form wall just after it emerges from theslip form.

The need also exists for an apparatus which slip-forms a wall andconcurrently creates patterns or impressions in both surfaces of thesidewalls and in the top wall.

The need also exists for an apparatus which includes an impressionroller which is easily and quickly interchangeable with anotherimpression roller, to create a wide variety of different patterns orimpressions in a slip-formed wall.

The need further exists for a two-stage impression roller for use withan apparatus manufacturing a slip-formed concrete wall, whichconcurrently creates patterns or impressions both in the surface of avertical sidewall portion and in the surface of an angled stem portionof the wall.

Lastly, the need exists for an impression roller for use with anapparatus manufacturing a slip-formed concrete wall, creating asubstantially continuous pattern or impression which repeats along theextent of the wall.

SUMMARY OF THE INVENTION

The present invention provides both an apparatus and a method forimpressing three-dimensional patterns in the exposed surface of aslip-formed concrete wall.

At least one impression roller is provided at the discharge end of theslip form. The roller includes a rigid inner form, preferablyright-circular cylindrical in configuration. The inner form has an axisof rotation, which is maintained in generally parallel relation to theexposed surface of the wall.

An outer layer or coating of resilient material, such as silicon, isprovided on the outer surface of the inner form. Typically, the layer ispre-cast on a shallow, horizontal casting frame. The casting frame isprovided with a lower surface, configured in an aesthetically pleasingpattern. The material is filled to the top edge of the frame, forming alower patterned side and an upper flat side. After the layer of materialhas cured, the layer is removed from the casting frame. The flat side ofthe resilient layer is then adhesively applied entirely around the outersurface of the inner form of the roller, so that the patterned side ofthe layer faces outwardly.

Virtually any pattern may be used, but typical patterns include a randomarrangement of stones and mortar lines, a linear arrangement of bricksand mortar lines, and geometric designs comprised of straight or curvedlines. The pattern may also include matching edge portions, along avertical line extending from the top to the bottom of the impressionroller. In this instance, the patterns along one mating edge of thelayer match the patterns along the other mating edge of the layer.

The impression roller is preferably mounted to the same movable framewhich supports and transports the slip-form. The roller is adjustablymounted to the frame, and positioned so that the outer peripheralportion of the roller depresses slightly into the outer surface of thewall just as the freshly-formed wall emerges from the slip-form. Owingto the surface engagement between the wall surface and the outerperiphery of the impression roller, the roller rotates continuously withthe relative movement between the roller and the slip-formed wall. As aconsequence, successive portions of the uncured, wet concrete areimpressed with a pattern which corresponds to the pattern on theimpression roller.

The outer surface of the roller is continuously sprayed with a liquidrelease agent, so the wet concrete will not stick to the roller surface.Alternatively, a film material, such as VISQUINE, may be continuouslyrolled out over the surface of the wet concrete before the roller comesinto contact with the exposed surface of the wall. In this way, theroller will not come into direct contact with the wet concrete, and theroller surface will not attract or become fouled with concrete. Later,after the concrete has at least partially cured, the film material ispeeled from the wall and the impressed pattern is apparent.

If the pattern includes matching edges, the pattern will continuouslyand seamlessly repeat itself along the wall surface. Entirely differentpatterns may be used across the horizontal or vertical extent of theimpression roller. Additional rollers may be used to impress patterns onopposing vertical wall surfaces, as well as upon the top wall surface.Also, a two-stage impression roller, having one surface parallel to theroller axis and another surface angled with respect to the roller axis,may be used to form impressions simultaneously in a vertical wall and inits angled supporting foot portion.

These and other features of the invention will now be described infurther detail in the drawings and the detailed description of thepreferred embodiment to follow.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a right rear perspective view of a slip-form machine fittedwith the sidewall and the top wall impression rollers of the presentinvention.

FIG. 2 is a perspective view showing the adjustable mounting arrangementfor the three impression rollers and the slip-form.

FIG. 3 is a side elevational view, particularly showing the top sideroller and its adjustable mounting feature.

FIG. 4 is a rear elevational view, showing the three impression rollers,the slip-form, and the slip-formed wall with its footing.

FIG. 5 is a top plan view of the sidewall impression rollers, showingtheir adjustable mounting feature.

FIG. 6 is a fragmentary perspective view of an end of an impressionroller, showing an edge portion of the adhesively applied silicon layerpartially peeled away.

FIG. 7 is a top plan view of a sidewall impression roller, the releaseagent spray bar, and the slip-form.

FIG. 8 is a top plan view of a sidewall impression roller, the VISQUINEroll, and the slip-form.

FIG. 9 is a side elevational view of a random stone and mortar patternimpressed in a slip-form wall, the broken center line representing thelocation of the matching edges, where the trailing edge of the firstrolled impression meets the leading edge of the second rolledimpression.

FIG. 10 is plan view of an alternative geometric pattern.

FIG. 11 is a plan view of an alternative brick and mortar pattern.

FIG. 12 is a plan view of yet another geometric pattern.

FIG. 13 is a rear elevational view of a slip-formed wall, in which onlya single impression roller is used to provide a pattern in one sidewall.

FIG. 14 is a rear elevational view of a tall slip-formed wall, showing atransition impression roller placing a pattern on one sidewall and uponthe supporting foot of the wall.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Turning now to FIG. 1, the apparatus 11 of the present inventionincludes a frame 12, supported for forward advancement over the groundby a number of continuous track drive feet 13. Because various machinesfor slip-forming walls or vertical barriers are well known in the art,their structure and operation will not be described in great detailherein. However, several key components are included in all suchmachines in one form or another, and they will be generally describedherein so as to further the understanding of the overall operation ofthe present invention.

A concrete elevator 14 is located at the forward end of the apparatus.Concrete 16 is delivered into the elevator 14 by means of a chute 17,extending from a concrete truck (not shown). The consistency of thisconcrete is quite viscous, having approximately a 1 ½″ slump. Inaddition, the concrete used for this application has a somewhat higherpercentage of aggregate than the normal concrete mix. Both of thesefactors ensure that when the concrete wall 18 or vertical barrieremerges from the slip-forming process, the wall will be entirelyself-supporting and cure without deformation.

A continuous supply of fresh wet concrete, delivered off the upper endof the elevator 14, is fed into an entry end 19 of a slip-form assembly21. Slip-form assembly 21 includes a pair of parallel side wall forms 22and 23, and a top wall form 24. Side wall forms 22 and 23 are spacedapart a distance corresponding to the transverse dimension of concretewall 18. Top wall form 24 is perpendicular to both of the side walls,and spans the transverse dimension between them.

A pair of side panels 26 and a pair of end panels 27 define an open tophopper, surrounding the entry end 19. The side and end panels areeffective to confine and accumulate a sufficient amount of concrete sothat the entry end of slip-form assembly 21 is maintained full ofconcrete at all times. Having a continuous oversupply of concretepresent in the entry end, helps to ensure that the slip-formed concretewall 18 will not contain side voids or internal air pockets. However, asthe concrete mixture is very dry and it contains significant amounts ofaggregate, manual agitation of the concrete within the slip-form is alsonecessary. An agitator, having an elongated mixing probe 28 shown inbroken line in FIG. 4, causes the dry concrete mixture to disperse andmix throughout the interior volume of the slip-form. Although the mixingprobe of only a single agitator is shown in the drawings, multiplemixing probes and agitators are typically employed in commercialslip-form machines.

As the concrete fills the slip-form assembly, the apparatus 11 advancesforwardly and continuously, along a predetermined path. For thatpurpose, a guide line 29 is vertically spaced from the ground, along thepath which is desired for the concrete wall 18. The guide line may belaid out in any direction or fashion, so that straight, angled, orcurved walls may be produced. Plural alignment rods 31, depending fromthe side of the apparatus 11, are maintained in contingent relation withguide line 29 as the apparatus advances forwardly.

The concrete wall formed by the process includes a first sidewall 32, anopposing, second sidewall 33, a top wall 34, and a footing 36. As thebottom edges of the slip form assembly 21 are maintained in verticallyspaced relation from the ground, concrete 16 passing downwardly throughthe slip-form pushes outwardly from beneath the slip form, naturallyforming the footing 36. The footing may be left with a rough, unfinishedsurface, which is later covered with dirt. A trench (not shown) may alsobe excavated beforehand, so that the footing rests within the trenchbelow grade. By the time the concrete reaches a discharge end 37 of theslip-form assembly 21, the concrete wall 18 is fully formed,self-supporting, and ready for curing. The concrete of the just-emergedwall is still wet, and has smooth vertical sidewalls and a smooth topwall.

The primary purpose of the present invention is to impress an aestheticthree-dimensional pattern into an exposed smooth surface of theslip-formed wall 18 before the concrete cures. To accomplish thatpurpose, sidewall impression rollers 38 and 39, and top wall impressionroller 41 are provided. Impression rollers 38, 39 and 41 are all ofsubstantially identical construction, although their sizes may vary withthe particular application. Thus, in the discussion to follow, identicalnumerals will be used to identify identical structural elements for thevarious impression rollers.

Sidewall impression roller 38 is elongated, and preferablyright-circular cylindrical in configuration. Roller 38 has an axis ofrotation 42 and a resilient outer periphery 43 impressed with athree-dimensional pattern. An axle 44 passes through an upper bearing 46and a lower bearing 47 at upper and lower ends of the roller 38, tosupport the roller for rotation about axis 42. An upper support arm 48and a lower support arm 49, are pivotally attached at their inner endsto respective portions of frame 12. Axle 44 is attached to the outerends of support arms 48 and 49.

Support arms 48 and 49 are adjustable about their pivotal attachments bymeans of a threaded rod assembly 51. Assembly 51 includes a threaded rod52, a threaded cylindrical stub 53, and a threaded captive ball coupler54. Cylindrical stub 53 is mounted for rotation on support arm 48. Thehousing of ball coupler 54 is affixed to a plate 56, but the captivethreaded ball is capable of rotating through a horizontal plane. Whenthreaded rod 52 is rotated in a first direction, outward lateral forcesare applied through stub 53 to move arm 48 and roller 38, away from slipform assembly 22. When rod 52 is rotated in a second direction, inwardlateral forces are applied through stub 53 to urge arm 48 and roller 38,toward slip form assembly 22. Owing to their rotational capabilities,ball coupler 54 and stub 53 allow rod 52 to make small rotationalexcursions through a horizontal plane, as inward or outward adjustmentsof the impression roller 38 are made. A substantially identicalconstruction is provided at the lower end of roller 38, to providelateral adjustments for support arm 49 and the lower end of roller 38.

Using the aforementioned adjustable support system, the positions ofrollers 38 and 39 are set so that their outer peripheries 43 arepartially depressed into an exposed surface of the wet concrete, as itemerges from the discharge end 37 of the slip form assembly 22. Inaddition, the axis of rotation 42 of rollers 38 and 39 are set so thatit is substantially parallel to the adjacent exposed surface of the wall18.

A similar arrangement is used to support top wall impression roller 41.One end of a pair of side support arms 45 supports roller 41 about itsaxis of rotation 42. An intermediate portion of the arms 45 is pivotallymounted to plates 56. A tensioning bolt 60 is provided at the end ofeach arm 45. Although gravity naturally presses impression roller 41into the top wall to a certain extent, tensioning bolt 60 provides afine adjustment for the extent of this impression, as indicated in FIG.3. Limit stop assembly 65, including an adjustable bolt and an abutmentplate, prevents impression roller 41 from extending too far into the topof the wall. Assembly 65 thereby works in conjunction with thetensioning bolt 60 to provide additional adjustable support for theroller 41, to ensure its proper vertical position with respect to thewall.

The impression rollers may be constructed in a number of different ways.It is preferred to employ a rigid, inner form 57, such as that providedby a right-circular cylindrical drum. The drum may be hollow, solid, orfilled with honeycomb or foam reinforcement material. The inner form 57provides support and an arcuate shape for the resilient outer periphery43, containing the pattern to be impressed in the concrete wall.

The resilient outer periphery 43 may be made from a moldable layer 58 ofsilicon-based material. It is preferred to use silicon-based material,or a functionally equivalent material, as it is curable from a liquidinto a resilient layer. Through the use of a framed planar mold, anydesired pattern may be formed in the lower surface of the mold. Then,the liquid silicon material, along with a curing agent, is poured intothe mold. The liquid silicon is added to the fill the form until thelayer is sufficiently thick and a planar upper surface is formed. Afterthe silicon layer has fully cured, it may be peeled away from the mold.Then, through the use of a spray or brush-applied adhesive, the planarupper surface of layer 58 is wrapped around the right-circularcylindrical outer surface 59 of inner form 57 (see, FIGS. 2 and 6). Inthis manner, layer 58 substantially covers the outer surface of the form57.

Virtually any type of three-dimensional pattern may be formed in thelayer 58. For example, a pattern representing a plurality of randomstone shapes 61 separated from each other by respective mortar lines 62,is shown in the impression rollers in FIG. 2. Of course the impressionin the layer 58 is the negative of that which is impressed in theconcrete wall. Thus, the random stone shapes 61 are depressed regions,and the mortar lines 62 are raised regions, as is most evident in FIG.6.

Other examples of three-dimensional patterns for the layer applied to animpression roller are shown in FIGS. 10-12. A layer 63, displaying ageometric pattern of straight, intersecting lines 64, is indicated inFIG. 10. Depending upon the desired impression in the concrete wall, thelines in the layer may be either raised or depressed. The layer 66 shownin FIG. 11, illustrates a brick 67 and mortar 68 pattern. To create amore realistic impression, the rectangular brick portions would bedepressed and the dividing mortar portions would be raised, in themolded layer 66. In that way, the opposite three-dimensional patternwould be impressed in the concrete wall. Yet another example of a layer69 is depicted in FIG. 12. In this pattern, upper lines 71 are arrangedin horizontal alignment, and lower lines 72 are arranged in verticalalignment. It should be apparent that by using such a system, where thepattern is molded into a layer forming the outer periphery of theimpression roller, the greatest flexibility in accomplishing the objectsof the invention is achieved.

However, alternative constructions for the impression roller may beused. Rather than applying a separate molded layer to the roller, athree-dimensional texture could be sprayed onto all or part of theroller. Three dimensional objects, themselves containing patterns orproviding an object pattern, could be affixed to the outer surface ofthe roller, either mechanically or adhesively. Also, the impressionroller itself may be configured with flat sectors, or sections, toprovide a three-dimensional pattern.

It has been determined that a resilient layer or coating is asignificant feature for the impression roller of the present invention.Thus, irrespective of the configuration or construction of the roller,having a resilient outer periphery is necessary to form high-qualitythree-dimensional impressions in slip-formed walls. This stems primarilyfrom the constituent makeup of the concrete 16 used in the slip-formprocess. As the concrete 16 is a very dry mix and includes moreaggregate than a normal mix, an impression roller having a rigid outerperiphery would tend to dislodge the aggregate and disrupt the integrityof the wall. The resilient layer, on the other hand, gives way when itencounters aggregate and smoothly rolls over such obstructions.

Returning now to FIG. 2, a release agent spray bar 73 is shown. Spraybar 73 is located adjacent the discharge end 37 of the slip-frameassembly, so that a small amount of liquid release agent may be appliedto all walls of the concrete wall 18 which are to be impressed with apattern. (See, FIG. 7). Without the use of a release agent, the dryconcrete mix tends to adhere to the impression roller, and deface thesurface of the concrete wall. Spray bars 73 are therefore used not onlyfor each of the sidewall impression rollers 38 and 39, but also for thetop wall roller 41. As shown in FIG. 1, a release agent tank 74 and apump 76 are mounted on the frame 12. Pump 76 provides a continuoussupply of release agent to each of the spray bars.

An alternative to the use of a liquid spray release agent is shown inFIG. 8. A roll 77 of a thin plastic film 78, such as VISQUINE, ismounted on a roll axle 78, secured between upper support arm 48 andlower support arm 49. The plastic film is captured between theimpression roller and the concrete wall and sticks to the wet concreteafter the impression is made. The film protects the outer periphery ofthe impression roller from being fouled during the impression process.Then, after the concrete in the wall has partially cured, the film isgently removed from the wall leaving the three-dimensional impressionintact.

It should be apparent now that when the apparatus 11 is advancedforwardly, the support system for the impression rollers is advanced atthe same speed and in the same direction as slip form assembly 22. Owingto this forward advancement and the surface engagement between the outerperiphery of each of the impression rollers and the exposed surface ofthe wet concrete, each of the impression rollers is caused to rotate.With this rotation of the impression rollers, successive portions oftheir outer peripheries impress successive portions of the concrete wallwith the three-dimensional pattern.

In carrying out the method of the present invention, the following stepsare followed for continuously impressing a three-dimensional patterninto a slip-formed concrete wall: (1) continuously slip-forming aconcrete wall, in which the concrete wall has parallel side walls and atop wall, with the top wall spanning a transverse distance between theside walls; (2) maintaining a layer of resilient material having athree-dimensional pattern therein in an arcuate configuration, theresilient layer having an axis of rotation; (3) partially depressing theresilient layer into an exposed surface of the concrete wall justemerging from the slip form, providing surface engagement between thepattern and the exposed surface; (4) continuously rotating the layer ofresilient material about its axis of rotation, at the same rate as thewall continues to emerge from the slip-form; and, (5) maintaining theaxis of rotation in substantially parallel relation to the exposedsurface, so that a successive portion of the pattern will impress asuccessive exposed portion of the concrete wall.

FIG. 13 shows an implementation of the apparatus 11 of the presentinvention in which only a single sidewall impression roller 81 isemployed. In this application, the three-dimensional pattern is onlyrequired to be impressed on one sidewall. In addition, the slip-formedconcrete wall 82 is somewhat higher than that shown in the previousexample. For these reasons, a slight modification is made to theslip-form assembly 83.

In the earlier described version of the invention, where an opposingpair of sidewall impression rollers 38 and 39 was employed, the lateralforces imposed against the wall 16 were opposing and equal. However, thelateral forces applied by the single impression roller 81 against thesidewall of the concrete wall 82 are unopposed. This circumstance isexacerbated by the fact that wall 82 is fairly high, making lateraldisplacement of the wall under the forces of the impression roller evenmore likely. Through the simple expedient of extending the length of theopposing side wall form 84, a force equal and opposing to forces imposedby the impression roller 81 is presented. In other words, side wall form84 extends outwardly and downstream from the main slip form assembly 83,a distance slightly past the point where the outer periphery of theimpression roller 81 engages the exposed surface of the wall 82. In thismanner, the wall 82 will be fully laterally supported during theimpression process. In all other respects, the features and operation ofthe apparatus shown in FIG. 13 is identical to that previouslydescribed.

Yet another specialized application of the apparatus of the presentinvention is shown in FIG. 14. When a particularly tall slip-formedconcrete wall 86 is to be made, a separate footing 87 is first poured,incorporating a reinforcement steel bar structure 88. Then, on a secondpass of the apparatus, the concrete wall 86 is slip-formed so as toencompass and surround, the bar structure 88.

To provide additional strength and stability, it is desirable to form aflared-out skirt 89, at the base of the wall 86. Accordingly, slip-formassembly 91 includes a special extended side wall form 92 with anoutwardly directed portion 93 to form one side of the side wall. Theother side wall form (not shown), includes a complementary outwardlydirected portion so as to form the other side of the skirt 89.

For the purpose of impressing a three-dimensional pattern in one side ofthis compound angled wall 86, a two-stage sidewall impression roller 94is provided. Impression roller 94 includes an upper roller 96, which iselongated, and right-circular cylindrical in configuration. Roller 94also includes a lower roller 97, which is frusto-conical inconfiguration. The rollers 96 and 97 are joined together, so as torotate together at the same speed. As is evident from FIG. 14, upperroller 96 impresses a three-dimensional pattern in the exposed surfaceof the upper vertical section of wall 86, and lower roller 97 impressesa three-dimensional pattern on the exposed surface of the flared-outskirt 89. Of course, merely by adding another sidewall roller and a topwall roller, all three exposed surfaces of the wall 86 could beimpressed with a three-dimensional pattern.

It will be appreciated, then, that I have described an apparatus and amethod, for impressing aesthetically pleasing three-dimensional patternsin a slip-formed concrete wall.

1-23. (canceled)
 24. A method for continuously impressing a pattern intoa slip-formed concrete wall, comprising: continuously slip-forming aconcrete wall, the concrete wall having opposing side walls and a topwall, said top wall spanning a transverse distance between said opposingside walls; partially depressing a first patterned surface into a firstexposed surface of one of said opposing side walls; advancing said firstpatterned surface along said concrete wall to impress successiveportions of said first exposed surface with the first patterned surfaceas the wall is formed.
 25. A method as recited in claim 24, furthercomprising: engaging a second exposed surface opposite the first exposedsurface while the first exposed surface is impressed with the firstpatterned surface.
 26. A method as recited in claim 25, wherein engaginga second exposed surface comprises supporting the second exposed surfacewhile the first exposed surface is impressed with the first patternedsurface.
 27. A method as recited in claim 26, wherein the second exposedsurface is supported with a side wall form extending adjacent to thesecond exposed surface and opposite to said first exposed surface.
 28. Amethod as recited in claim 25, wherein engaging a second exposed surfacecomprises partially depressing a second patterned surface into thesecond exposed surface.
 29. A method as recited in claim 24, wherein:said first patterned surface is arcuate; said first patterned surfacehaving an axis of rotation substantially parallel to said first exposedsurface; and wherein advancing said first patterned surface along saidconcrete wall comprises rotating said first patterned surface about saidaxis so that successive portions of said first patterned surface impresssuccessive exposed portions of said first exposed surface.
 30. A methodas recited in claim 29, wherein: said arcuate surface has a threedimensional pattern; and wherein partially depressing a first patternedsurface comprises rolling the arcuate surface along first exposedsurface to create a three dimensional impression in the first exposedsurface.
 31. A method as recited in claim 28, further comprising:partially depressing a third patterned surface into a third exposedsurface; the third exposed surface being on the same side wall as thefirst exposed surface and oriented at an angle with respect to the firstexposed surface.
 32. A method as recited in claim 31, furthercomprising: partially depressing a fourth patterned surface into afourth exposed surface; the fourth exposed surface being on the sameside wall as the second exposed surface and oriented at an angle withrespect to the second exposed surface.
 33. A method as recited in claim28, further comprising: partially depressing an upper patterned surfaceinto an upper exposed surface; the upper exposed surface being on thetop wall spanning the opposing side walls.
 34. A method as recited inclaim 24, further comprising: applying a release agent to the concretewall prior to depressing the first patterned surface into the firstexposed surface.
 35. A method as recited in claim 24, furthercomprising: applying a plastic film to the concrete wall prior todepressing the first patterned surface into the first exposed surface.36. A method for impressing a pattern into a concrete wall emerging froma slip-form, the concrete wall having parallel opposing side walls and atop wall, said top wall spanning a transverse distance between saidopposing side walls, comprising: partially depressing a first patternedsurface into a first exposed surface of one of said opposing side wallsemerging from the slip-form; and advancing said first patterned surfacealong said concrete wall to impress successive portions of said firstexposed surface with the first patterned surface.
 37. A method asrecited in claim 36, wherein the first patterned surface is advanced atthe same rate as the formation of the wall emerging from the slip-form.38. A method as recited in claim 36, further comprising: engaging asecond exposed surface opposite the first exposed surface while thefirst exposed surface is impressed with the first patterned surface. 39.A method as recited in claim 38, wherein engaging a second exposedsurface comprises supporting the second exposed surface while the firstexposed surface is impressed with the first patterned surface.
 40. Amethod as recited in claim 39, wherein the second exposed surface issupported with a side wall form extending adjacent to the second exposedsurface and opposite to said first exposed surface.
 41. A method asrecited in claim 38, wherein engaging a second exposed surface comprisespartially depressing a second patterned surface into the second exposedsurface.
 42. A method as recited in claim 36, wherein: said firstpatterned surface is arcuate; said first patterned surface having anaxis of rotation substantially parallel to said first exposed surface;and wherein advancing said first patterned surface along said concretewall comprises rotating said first patterned surface about said axis sothat successive portions of said first patterned surface impresssuccessive exposed portions of said first exposed surface.
 43. A methodas recited in claim 42, wherein: said arcuate surface has a threedimensional pattern; and wherein partially depressing a first patternedsurface comprises rolling the arcuate surface along first exposedsurface to create a three dimensional impression in the first exposedsurface.
 44. A method as recited in claim 40, further comprising:partially depressing a third patterned surface into a third exposedsurface; the third exposed surface being on the same side wall as thefirst exposed surface and oriented at an angle with respect to the firstexposed surface.
 45. A method as recited in claim 44, furthercomprising: partially depressing a fourth patterned surface into afourth exposed surface; the fourth exposed surface being on the sameside wall as the second exposed surface and oriented at an angle withrespect to the second exposed surface.
 46. A method as recited in claim36, further comprising: applying a release agent to the concrete wallprior to depressing the first patterned surface into the first exposedsurface.
 47. A method as recited in claim 36, further comprising:applying a plastic film to the concrete wall prior to depressing thefirst patterned surface into the first exposed surface.
 48. A method forimpressing a pattern into a concrete wall emerging from a slip-form, theconcrete wall having parallel opposing side walls and a top wall, saidtop wall spanning a transverse distance between said opposing sidewalls, comprising: continuously impressing a three-dimensional patterninto successive portions of a first exposed surface of one of saidopposing side walls emerging from the slip-form; and engaging a secondexposed surface opposite the first exposed surface while the firstexposed surface is impressed with the three-dimensional pattern.
 49. Amethod as recited in claim 48, wherein engaging a second exposed surfacecomprises supporting the second exposed surface while the first exposedsurface is being impressed with the three-dimensional pattern.
 50. Amethod as recited in claim 49, wherein the second exposed surface issupported with a side wall form extending adjacent to the second exposedsurface and opposite to said first exposed surface.
 51. A method asrecited in claim 48, wherein engaging a second exposed surface comprisesimpressing a three-dimensional pattern into the second exposed surface.52. A method as recited in claim 48, wherein the first exposed surfaceis impressed at the same rate as the formation of the wall emerging fromthe slip-form.
 53. A method as recited in claim 48, wherein continuouslyimpressing a three-dimensional pattern comprises: partially depressing apatterned surface into the first exposed surface; and advancing saidpatterned surface along said concrete wall to impress successiveportions of said first exposed surface with the patterned surface.
 54. Amethod as recited in claim 53, wherein: said patterned surface comprisesthe periphery of an impression roller; said impression roller having anaxis of rotation substantially parallel to said first exposed surface;and wherein advancing said patterned surface along said concrete wallcomprises rotating said impression roller about said axis whilemaintaining engagement of said patterned surface with the first exposedsurface so that successive portions of said patterned surface impresssuccessive exposed portions of said first exposed surface.